This invention relates to a belt conveyor, and particularly to a belt conveyor usable for removing a blank formed in a blanking die.
U.S. Pat. No. 4,912,959, issued to me on Apr. 3, 1990, discloses a belt conveyor extending into the opening between a vertically-movable upper die and a stationary die for removing a blank formed out of a steel sheet during the downstroke of the upper die. The upper die is equipped with an array of suction cups that lift the steel blank into engagement with the lower run of the belt conveyor. An electromagnet means located above the lower run of the belt conveyor holds the steel blank against the belt lower surface as the belt moves the blank out of the opening between the upper and lower dies. When the blank is approximately half way out of the opening between the upper and lower dies, a permanent magnet means takes over from the electro-magnet means to hold the steel blank against the belt lower surface until the steel blank is transferred onto an external conveyor.
The present invention relates to an improvement on the belt conveyor disclosed in my U. S. Pat. No. 4,912,959. In the present invention the suction cups and electromagnet means are replaced with a permanent magnet means, to reduce the initial equipment cost and subsequent maintenance expense. The belt conveyor means is mounted for vertical synchronized motion with the upper die, so that while the upper die is cutting through the steel sheet (to form the steel blank), the permanent magnet means comes into close proximity to the steel blank. As the upper die begins its upstroke, the permanent magnet means lifts the steel blank into facial engagement with the lower surface of the conveyor belt.
When the lower run of the conveyor belt is spaced a suitable distance above the lower die, the motor for the conveyor is energized to enable the conveyor to transport the steel blank out of the opening between the upper and lower dies. During this operation, the permanent magnet means hold the steel blank in facial engagement with the lower run of the conveyor belt.
The invention is advantageous in that the initial equipment cost is relatively modest. In addition, maintenance costs are somewhat decreased due to the overall design simplicity of the equipment.
Specific features of the invention will be apparent from the attached drawings and description of a preferred embodiment of the invention.